Flexible torque transmission couplings

ABSTRACT

This invention relates to resilient couplings of the type comprising a ring assembly of alternate rigid and resilient members clamped between two shaft coupling members adjacent rigid members of the ring assembly being connected to opposite shaft coupling members to provide a flexible torque transmission coupling. The rigid members of the ring assembly have a tooth which projects towards the shaft coupling member to which it is attached and abuts one side of a ridge which extends tangentially with respect to an annular ridge which surrounds the hole through which extends a bolt to clamp the two members together. This abutment prevents the rigid member of the ring assembly from rotating during clamping of the bolt so that the adjacent resilient elements of the ring assembly are not distorted during this clamping.

0 United States Patent 1 1 1111 3,750,422

Via 1 1 Aug. 7, 1973 [54] FLEXIBLE TORQUE TRANSMISSION 3,470,710 10/1969Feller et al 64/ll R COUPLINGS Primary Examiner-Charles J. Myhre [75]Inventor Carlo Milan Italy Assistant Examiner-Randall Heald [73]Assignee: So'cieta Appllcazioni Gommn Attorney-Richard C. Sughrue et al.

Antivlbrantl Saga S.p.A., Milan, Italy 221 Filed: May 30, 1972 [571ABSTRACT This invention relates to resilient couplings of the type [21]Appl' comprising a ring assembly of alternate rigid and resilientmembers clamped between 'two shaft coupling [30] F i A n fl P i it D tmembers adjacent rigid members of the ring assembly Oct 28 1971 Italy It 30461 being connected to opposite shaft coupling members to provide aflexible torque transmission coupling. The 52 us. c1 64/11 R 64/13 64/14rigid members assembly have a whih 51 Int. Cl. .3 F1611 3 28 Pmieciswards the shaf member which 58 Field of Search.......................:64/13 12 11 R it is attached and abuts side a ridge which tendstangentially with respect to an annular ridge which surrounds the holethrough which extends a bolt [56] References Cited to clamp the twomembers together. This abutment prevents the rigid member of the ringassembly from UNITED STATES PfATENTS rotating during clamping of thebolt so that the adjag; :aliceschem cent resilient elements of the ringassembly are not disarone t 3,353,373 11/1967 Schumacher et al. 64/11 Rdulmg clamp'ng' 3,425,240 2/1969 Feller et al 64/11 R 1 Claim, 4 DrawingFigures PATENTEDMIB 1 um I 750.422

sum 1 or z PATENTEmus nan SHE 2 0f 2 3.750.422

BACKGROUND OF THE INVENTION The present invention relates to resilientcouplings for the transmission of torque, and particularly to couplingsof the type which comprise a resilient element to which two rigidcoupling members are attached, the resilient element being in the formof a ring of small resilient elements interconnected by means of rigidlink elements each of which has an axial opening through which extends abolt which connects the resilient ring to one of the rigid couplingmembers.

In order to prevent rotation of the link elements around theirrespective bolts during the assembly of the resilient ring to the rigidshaft coupling members so as to avoid the consequent harmful distortionsof the flexible ring, it has been proposed, and described in ItalianPat. No. 613,033 that each rigid link element should be provided with anaxially projecting rigid tooth in a position which is slightly eccentricwith respect to the hole for the teeth; adjacent link elements extendingin opposite directions into cooperating recesses formed in the arms ofthe corresponding shaft coupling member.

Although resilient couplings of this type satisfactorily solve thistechnical problem, they have one disadvantage in that assembly anddisassembly of the coupling requires relative axial movement of theshaft coupling members due to the fact that the recesses into which theteeth on the link elements have to fit, or from which they have to beremoved, are located parallel to the axis of the respective couplingmember. This axial movement of the coupling members is inconvenient, andin some cases may not be possible.

SUMMARY OF THE INVENTION According therefore to the present invention,there is provided a resilient torque transmission coupling of the typecomprising an annular resilient assembly to which the arms of two rigidshaft coupling members are attached, the annular resilient assemblybeing formed of a plurality of resilient elements interconnected in aring by a corresponding number of link elements each of which has anaxial opening through which extends a respective bolt which extends intoa hole in an arm of one or other of the shaft coupling members andconnects the annular resilient assembly thereto, there being providedmeans for preventing rotation of the link elements during assemblythereof to the shaft coupling members characterised in that the rotationpreventing means comprise an axial tooth on each link element and anannular ridge surrounding each hole in the shaft coupling membersagainst each of which abuts the end of a respective link element, eachannular ridge having an associated tangential ridge against one side ofwhich the axial tooth in the associated link member abuts, the said oneside of the tangential ridge being substantially parallel to a planeparallel to the axis of the shaft coupling member and passing throughthe centre of the said hole in the shaft coupling member and the centreof the shaft coupling member and being displaced slightly from thisplane in the direction of tightening rotation of the thread on the bolt,the annular ridge, the tangential ridge and the length of the said toothbeing substantially the same.

Various other features and advantages of the invention will becomeapparent during the course of the following description with referenceto the accompanying 2 drawings which is given purely by way ofnonrestrictive example.

BRIEF DESCRIPTION OF THE DRAWINGS pling members of the resilientcoupling shown in FIG.

1; and

FIG. 4 is an end view of the shaft coupling member shown in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT The coupling illustrated in thedrawings comprises a resilient hexagonal annular assembly I to which'areattached two shaft coupling members 2, 3, each of which consists of aboss 2a, 3a respectively, and three arms 2b, 3b respectively. The anglebetween adjacent arms of each shaft coupling member is The resilientannular assembly comprises a number of small rubber blocks 4, adjacentblocks being connected to each other by means of rigid link members 5each of which has an axial hole 5a for a bolt 6 which connects theassembly 1 to one of the shaft coupling members.

Each bolt 6 is screwed at one end 6a into a threaded hole 11 in one ofthe arms of one of the shaft coupling members, and is threaded at theother end to receive a clamping nut 7. Each link member 5 has a tooth 5bextending axially in an eccentric position with respect to the centre ofthe hole 50: the teeth 5b of adjacent link members 5 extend in oppositedirections since adjaeent link members are attached to opposite shaftcoupling members.

The means for preventing rotation of the link members 5 during assemblyof the resilient ring to the shaft coupling members will be describedwith particular reference to FIGS. 2 and 4 which show the shaft couplingmember 3. The arms 3b each have, upon the surface which faces theannular resilient assembly, an annular ridge 8 which surrounds and iscoaxial with the threaded hole 11. The ridge 8 abuts the correspondinglink member 5 when the coupling is assembled and has an associated ridge9 extending in a tangential direction, thereto. One side 10 of thetangential ridge 9 is positioned parallel to a plane which passesthrough the axis of the shaft coupling member and through the axis ofthe hole I1, and is spaced from this plane in the direction of rotationcorresponding to tightening of the thread of the nut 7, by a distanceroughly equal to the thickness of the tooth Sb and abuts the side of thetooth 5b when the coupling is assembled; the height of the tangentialridge 9 and the length of the tooth 5b are approximately the same.

In the embodiment shown in the drawings the position of the abuttingsurface 10 of the tangential ridge 9 corresponds to a right hand threadof the nuts 7. It will be seen that as the nuts 7 are being screwed upthe abutting surfaces 10 of the ridges 9 prevent the link elements 5from rotating upon their respective bolts 6. Assembly and disassembly ofthe coupling described above can be effected without requiring relativeaxial movement of the shaft coupling members simply by angular movementof one of the shaft coupling members.

Assembly of the flexible coupling is as follows: Firstly the two shaftcoupling members 2, 3, are to be located in their operating positionsand then one of the two shaft coupling members is rotated by about 30 sothat resilient annular assembly 4 can be fitted between them, the shaftcoupling member which was displaced is then rotated in the oppositedirection until the teeth 5b are brought into contact with the abutmentsurfaces of the tangential ridges 9. The nuts 7 are then 10 in saidshaft coupling members,

the improvement wherein there is provided an axially extending tooth oneach said rigid member of said annular assembly, the tooth on adjacentsaid rigid members of said annular assembly extending in opposite axialdirections,

an annular ridge surrounding each said hole in said shaft couplingmembers,

a further ridge tangential to said annular ridge, said further ridgehaving one face substantially parallel to an axial plane passing throughthe centre of said hole in said shaft coupling member and through thecentre of said shaft coupling member but displaced therefrom in thedirection of tightening rotation of the thread on said bolts wherebysaid teeth on said rigid members of said annular assembly, and said onefaces of said ltange'ntial ridges on said shaft coupling members abut toprevent rotation of said rigid member of said annular assembly duringtightening of said bolts, the height of said annular and tangentialridges being substantially equal to the axial length of said teeth.

a a a a a

1. In a resilient torque transmission coupling of the type comprising an annular assembly of alternate rigid members and resilient members, said rigid members having holes therethrough, and two rigid shaft coupling members having holes therein, said annular assembly being attached between said shaft coupling members by means of bolts extending through said holes in said rigid members of said annular assembly into said holes in said shaft coupling members, the improvement wherein there is provided an axially extending tooth on each said rigid member of said annular assembly, the tooth on adjacent said rigid members of said annular assembly extending in opposite axial directions, an annular ridge surrounding each said hole in said shaft coupling members, a further ridge tangential to said annular ridge, said further ridge having one face substantially parallel to an axial plane passing through the centre of said hole in said shaft coupling member and through the centre of said shaft coupling member but displaced therefrom in the direction of tightening rotation of the thread on said bolts whereby said teeth on said rigid members of said annular assembly, and said one faces of said tangential ridges on said shaft coupling members abut to prevent rotation of said rigid member of said annular assembly during tightening of said bolts, the height of said annular and tangential ridges being substantially equal to the axial length of said teeth. 